It should matter! You're supposed to be the hero!

Or do you not care about the fact that Xion literally chose to go back to you!?

[It's probably an unfair question. Because even though Namine has told him about Xion, those memories have not come back to him. And it's not like Sora knew her. But he's a little past the point of being rational right now, like a snowball gathering speed down a hill. The weight of knowing about Xion combined with Axel leaving and buried resentments are all starting to come to the surface.]